Screening for the Early Detection of Disease in Individuals Exposed to Vinyl Chloride

摘要

A prospective collaborative study was conducted to compare the effectiveness of four clinical techniques in the detection of liver damage due to vinyl chloride monomer exposure. A chemically exposed and medically monitored worker population was identified by histopathological and biochemical documentation. Three techniques were non-invasive: (a) grey scale ultrasonography of the liver, (b) microvasular skin capillary assessment, and (c) urinary analysis of glycosaminoglycan excretion. The fourth technique was the standard 99mTc sulfur colloid radionucleotide liver spleen scan. The screening studies were performed on a randomly selected single cohort of chemical workers. All four techniques were analyzed for their sensitivity and specificity as compared to results of the liver biopsy and biochemical blood test classification. Although all four screening techniques had a sensitivity and specificity sum greater than one, none were significantly better than could be explained by chance or the use of the biased coin. Reclassification of the population into those with more severe biochemical abnormalities improved the sensitivity of all screening tests, but only the sensitivity and specificity sum for the GAG test statistically significant at the 0.05 level. There was no significant correlation between any pair of screening test. None of the four screening tests agreed with the biopsy results better than might be obtained by biased coin or chance. These screening studies as presently constituted, do not provide sufficient sensitivity and specificity to warrant their use in community screening for subclinical asymptomatic hepatic injury due to chemical exposure.